I'm not so sure it was so prime back in the early/mid 80s when it was initially being planned. It was certainly, at about a mile, considered too far from the city station for the government employees used to commuting by rail/tube. When it first opened there was a fleet of shuttle buses that ran between Quarry House and the Station and I think they still run today if much less frequently. I also seem to recall talk of a station in the Marsh Lane area to service it.

It was built between 89 and 93.and a fair percentage of the workforce migrated north.

If the door gives access to electrics, it would have Health and Safety warning signs and Emergency contact details. There are no street lighting or illuminated signs on the flyover. The surface water drainage is via kerb stones which have inlets for the rain and a continuous drain running just behind/below the kerb. It is likely that there are no utilities below the flyover, the doors are probably for engineers to check the integrity of the structure.

tyke bhoy wrote: ... It was built between 89 and 93.and a fair percentage of the workforce migrated north.

I used to know somebody who worked there and the idea was to decentralise government. However, the top civil servants stayed in London so people in the next rank down were constantly travelling to London for meetings with them. Perhaps that's changed with modern IT